Genome-wide maps of HES1 binding-site in human chondrogenic cell.
Ontology highlight
ABSTRACT: Notch signaling modulates skeletal formation and osteoarthritis (OA) development through induction of catabolic factors. Here we examined functional roles of Hes1, the representative downstream transcription factor of Notch signaling, during these processes. Chromatin immunoprecipitation-sequencing (ChIP-seq) identified resposive elements of Hes1 around gene loci of Mmp13 and Adamts5, which were catabolic enzymes of cartilage matrix. Examination of HES1 binding site in human chondrogenic SW1353 cells.
Project description:Notch signaling modulates skeletal formation and osteoarthritis (OA) development through induction of catabolic factors. Here we examined functional roles of Hes1, the representative downstream transcription factor of Notch signaling, during these processes. Chromatin immunoprecipitation-sequencing (ChIP-seq) identified resposive elements of Hes1 around gene loci of Mmp13 and Adamts5, which were catabolic enzymes of cartilage matrix.
Project description:RNA-seq of FACS Sorted E10.5 Pdx1-GFP+ of genotypes wildtype and Hes1-/-. Summary statement The developmental mechanisms that cause ectopic pancreas are poorly understood. We show that aberrant dorsal pancreas morphogenesis in Hes1 mutants leads to ectopic pancreas depending on the pro-endocrine gene Neurog3. Abstract Mutations in Hes1, a target gene of the Notch signalling pathway, lead to ectopic pancreas by a poorly described mechanism. Here we use genetic inactivation of Hes1 combined with lineage tracing in mouse embryos to reveal an endodermal requirement for Hes1 and that most ectopic pancreas tissue is derived from the E8.5 dorsal pancreas primordium. RNA-seq data from sorted E10.5 Pdx1-GFP+ cells from Hes1+/+ and Hes1−/− suggested that upregulation of endocrine lineage genes in Hes1−/− embryos was the major defect in the endoderm and accordingly early pancreas morphogenesis was normalised and the ectopic pancreas phenotype suppressed in Hes1−/−Neurog3−/− embryos. Analysis of other Notch pathway mutants uncovered a total depletion of progenitors in Mib1 deficient dorsal anlage, which was replaced by an anterior Gcg+ extension. Together, our results demonstrate that aberrant morphogenesis is the cause of ectopic pancreas and that a part of the endocrine differentiation program is mechanistically involved in the dysgenesis. Our results suggest that the ratio of endocrine lineage to progenitor cells is important for morphogenesis and that a strong endocrinogenic phenotype without complete progenitor depletion as seen in Hes1 mutants provokes an extreme dysgenesis that causes ectopic pancreas.
Project description:To formally address the biological activity of Hes1 in vivo, we tested the interaction between oncogenic NOTCH1 and acute Hes1 loss in a retroviral-transduction bone marrow transplantation model of NOTCH-induced T-ALL Forced expression of activated NOTCH1 in this model typically results in full leukemia transformation 5-10 weeks later. We performed microarray gene expression analysis of Hes1 wild type and Hes1-/- NOTCH1 induced leukemias
Project description:High levels of Hes1 expression are frequently found in BCR-ABL-positive chronic myelogenous leukemia in blast crisis (CML-BC). In mouse bone marrow transplantation (BMT) models, co-expression of BCR-ABL and Hes1 induces CML-BC–like disease; however the underlying mechanism remained elusive. Here, based on gene expression analysis, we show that MMP-9 is upregulated by Hes1 in common myeloid progenitors (CMPs). Analysis of promoter activity demonstrated that Hes1 upregulated MMP-9 by activating NF-kB. Analysis of 20 samples from CML-BC patients showed that MMP-9 was highly expressed in three, with two exhibiting high levels of Hes1 expression. Interestingly, MMP-9 deficiency impaired the cobblestone area-forming ability of CMPs expressing BCR-ABL and Hes1 that were in conjunction with a stromal cell layer. In addition, these CMPs secreted MMP-9, promoting the release of soluble Kit-ligand (sKitL) from stromal cells, thereby enhancing proliferation of the leukemic cells. In accordance, mice transplanted with CMPs expressing BCR-ABL and Hes1 exhibited high levels of sKitL as well as MMP-9 in the serum. Importantly, MMP-9 deficiency impaired the development of CML-BC–like disease induced by BCR-ABL and Hes1 in mouse BMT models. The present results suggest that Hes1 promotes the development of CML-BC, partly through MMP-9 upregulation in leukemic cells. Common myeloid progenitors (CMPs; Lineage negative, c-Kit positive, Sca-1 negative, Fc-gamma-receptor low, CD34 positive fraction) were sorted with a FACSAria cell sorter (Becton Dickinson). Retroviruses were generated by transfecting Plat-E packaging cells with retrovirus vector pMYs-Hes1-IRES-GFP or empty vector (pMYs-IRES-GFP) using FuGENE 6 (Roche Diagnostics). Infection of retrovirus harboring Hes1 (pMYs-Hes1-IRES-GFP) or empty vector (pMYs-IRES-GFP) into progenitors was performed using RetroNectin (Takara Bio). Hes1-transfected CMPs and Mock-transduced CMPs were isolated 36 hours after infection with a FACSAria cell sorter. One sample of Hes1-transfected CMPs and one sample of mock-transduced CMPs were analyzed with GeneChip Mouse Genome 430 2.0 Array.
Project description:We characterized the CDK9 and Hes1 occupancy on gene loci in conditions of unstimuated and LPS stimualtion in BMDMs BMDMs were left untreated or stimulated with LPS for 1 hour. CDK9 or Hes1 ChIP was performed and the DNA products were subject to ChIPseq
Project description:Notch signaling plays both oncogenic and tumor suppressor roles, depending on cell type. In contrast to T cell acute lymphoblastic leukemia (T-ALL), where Notch activation promotes leukemogenesis, induction of Notch signaling in B-ALL leads to growth arrest and apoptosis. The Notch target Hairy/Enhancer of Split1 (HES1) is sufficient to reproduce this tumor suppressor phenotype in B-ALL, however the mechanism is not yet known. Here we report that HES1 regulates pro-apoptotic signals via the novel interacting protein Poly ADP-Ribose Polymerase1 (PARP1) in a cell type-specific manner. The interaction of HES1 with PARP1 inhibits HES1 function, induces PARP1 activation and results in PARP1 cleavage in B-ALL. HES1-induced PARP1 activation leads to self-ADP ribosylation of PARP1, consumption of NAD+, diminished ATP levels, and translocation of the Apoptosis Inducing Factor (AIF) from mitochondria to the nucleus, resulting in apoptosis in B-ALL, but not T-ALL. Importantly, induction of Notch signaling via the Notch agonist peptide DSL can reproduce these events and leads to BALL apoptosis. The novel interaction of HES1 and PARP1 in B-ALL modulates the function of the HES1 transcriptional complex and signals through PARP1 to induce apoptosis. This mechanism reveals a cell type-specific pro-apoptotic pathway which may lead to Notch agonist-based cancer therapeutics.
Project description:Notch signaling plays both oncogenic and tumor suppressor roles, depending on cell type. In contrast to T cell acute lymphoblastic leukemia (T-ALL), where Notch activation promotes leukemogenesis, induction of Notch signaling in B-ALL leads to growth arrest and apoptosis. The Notch target Hairy/Enhancer of Split1 (HES1) is sufficient to reproduce this tumor suppressor phenotype in B-ALL, however the mechanism is not yet known. Here we report that HES1 regulates pro-apoptotic signals via the novel interacting protein Poly ADP-Ribose Polymerase1 (PARP1) in a cell type-specific manner. The interaction of HES1 with PARP1 inhibits HES1 function, induces PARP1 activation and results in PARP1 cleavage in B-ALL. HES1-induced PARP1 activation leads to self-ADP ribosylation of PARP1, consumption of NAD+, diminished ATP levels, and translocation of the Apoptosis Inducing Factor (AIF) from mitochondria to the nucleus, resulting in apoptosis in B-ALL, but not T-ALL. Importantly, induction of Notch signaling via the Notch agonist peptide DSL can reproduce these events and leads to BALL apoptosis. The novel interaction of HES1 and PARP1 in B-ALL modulates the function of the HES1 transcriptional complex and signals through PARP1 to induce apoptosis. This mechanism reveals a cell type-specific pro-apoptotic pathway which may lead to Notch agonist-based cancer therapeutics. Study involved the gene expression profiling of human acute lymphoblastic leukemia samples, and comparison of the levels of expression NOTCH1 pathway genes and targets across ALL subtypes
Project description:In leukemogenesis Notch signaling can be up- and down-regulated in a context-dependent manner. Here we report that deletion of hairy and enhancer of split-1 (Hes1) promotes acute myeloid leukemia (AML) development induced by the MLL-AF9 fusion protein. Subsequently, the FMS-like tyrosine kinase 3 (FLT3) was up-regulated in mouse cells of a Hes1- or RBP-J-null background. MLL-AF9-expressing Hes1-null AML cells showed enhanced proliferation and ERK phosphorylation following FLT3 ligand stimulation. FLT3 inhibition efficiently abrogated proliferation of MLL-AF9-induced Hes1-null AML cells. Furthermore, an agonistic anti-Notch2 antibody induced apoptosis of MLL-AF9-induced AML cells in a Hes1-wild type but not a Hes1-null background. These observations demonstrate that Hes1 mediates tumor suppressive roles of Notch signaling in AML development by down-regulating FLT3 expression.
Project description:In leukemogenesis Notch signaling can be up- and down-regulated in a context-dependent manner. Here we report that deletion of hairy and enhancer of split-1 (Hes1) promotes acute myeloid leukemia (AML) development induced by the MLL-AF9 fusion protein. Subsequently, the FMS-like tyrosine kinase 3 (FLT3) was up-regulated in mouse cells of a Hes1- or RBP-J-null background. MLL-AF9-expressing Hes1-null AML cells showed enhanced proliferation and ERK phosphorylation following FLT3 ligand stimulation. FLT3 inhibition efficiently abrogated proliferation of MLL-AF9-induced Hes1-null AML cells. Furthermore, an agonistic anti-Notch2 antibody induced apoptosis of MLL-AF9-induced AML cells in a Hes1-wild type but not a Hes1-null background. These observations demonstrate that Hes1 mediates tumor suppressive roles of Notch signaling in AML development by down-regulating FLT3 expression. 4 samples are analyzed, two pairs of MLL-AF9/Hes1-/- and MLL-AF9/Hes1+/+ leukemic bone marrows.
Project description:Notch signaling regulates several cellular processes including cell fate decisions and proliferation in both invertebrates and mice. However, comparatively less is known about the role of Notch during early human development. Here, we examined the function of Notch signaling during hematopoietic lineage specification from human pluripotent stem cells (hPSCs) of both embryonic and adult fibroblast origin. Using immobilized Notch ligands and siRNA to Notch receptors we have demonstrated that Notch1, but not Notch2 activation, induced HES1 expression and generation of committed hematopoietic progenitors. Using gain and loss of function approaches, this was shown to be attributed to Notch signaling regulation through HES1, that dictated cell fate decisions from bipotent precursors either to the endothelial or hematopoietic lineages at the clonal level. Our study reveals a previously unappreciated role for the Notch pathway during early human hematopoiesis, whereby Notch signaling via HES1 represents a toggle switch of hematopoietic vs. endothelial fate specification.